The Department of Health Evaluation Sciences at the Pennsylvania State University proposes to serve as the Data Coordinating Center (DCC) for the Pediatric Asthma Clinical Research Network (PACRN). The first specific aim is to provide biostatistical leadership and scientific coordination by proposing optimal trial designs, invoking procedures to remove/reduce systematic bias, projecting appropriate sample sizes, selecting methods of randomization, analyzing data for interim and final reports, collaborating on presentations and publications, developing and presenting training sessions, developing certification criteria for Clinical Center (CC) staff, collaborating on protocol development, overseeing the development of Manuals of Operations, collaborating on recruitment and retention strategies, and resolving protocol questions from CC staff. The second specific aim is to establish the PACRN computer network by using client server computing based on a wide-area network and a World-Wide Web program implementation. The third specific aim is to design and maintain the PACRN Database Application System (DBAS) that will allow CC staff to register subjects, enter and edit data, mark unresolvable checks, randomize subjects, and review subject status. The DBAS includes DCC-only applications to track the receipt of data collection forms, interactively verify data, define/modify rules for validation checks, execute validation, generate/track queries, edit data, tabulate protocol violations, identify forms for audit, and list unresolvable errors. The fourth specific aim is to develop and maintain the PACRN Data Quality Assurance and Monitoring Program by developing high-quality data forms, manuals, and subject handouts, training/certifying CC staff in PACRN procedures, shipping/tracking of biological specimens, supporting CC staff during PACRN trials, and performing site visits and data audits. The fifth specific aim is to provide project management and administrative support for the PACRN by facilitating communication, monitoring deadlines, organizing meetings and telephone conferences, coordinating training sessions, arranging for study drugs to be masked, labeled, packaged, and distributed, coordinating CC site visits, and coordinating the distribution of PACRN documents.